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目的分析HIV-1 B’亚型毒株Nef蛋白重要功能区及CTL表位氨基酸序列变异特征。方法从137例HIV-1感染者的血浆样本中提取病毒RNA,进行逆转录获得c DNA,再经巢式PCR扩增全长Nef基因并纯化测序。利用Bio Edit、Mega6.0软件分析所获得的Nef基因重要功能区的氨基酸变异,并比较所获得的Nef基因共享序列与我国B亚型Nef共享序列及国际B亚型Nef共享序列的CTL表位情况。结果 HIV-1 B’亚型毒株Nef蛋白N端豆蔻酰化信号区、蛋白酶加工区、酸性区、Pak结合区、Pxx P区等功能区氨基酸序列较为保守,但有3个功能区中存在变异率大于30%的氨基酸位点,其中长度可变区的21号密码子上的R被E/K/Q取代的变异率达56.21%(R21E 24.09%,R21K 19.71%,R21Q 12.41%),COPI结合区EE154-155的E154被K取代的变异率为32.85%,双亮氨酸基序Exxx LL160-165的S163被C取代率为30.66%。本研究所得的137条Nef蛋白的共享序列的CTL表位与我国HIV-1 B亚型的共享序列CTL表位一致,而与国际B亚型共享序列相比有两个肽段表位的氨基酸发生了变异。结论 HIV-1 B’亚型毒株Nef蛋白多数重要功能区及CTL表位的氨基酸序列较保守,但有3个功能区存在变异率大于30%的氨基酸位点,这种特性可能影响病毒致病作用。
Objective To analyze the amino acid sequence variation of important functional domains and CTL epitopes of Nef protein of HIV-1 B ’subtype strain. Methods The viral RNA was extracted from plasma samples of 137 HIV-1 infected individuals and was reverse transcribed to obtain c DNA. The full-length Nef gene was amplified by nested PCR and sequenced. The amino acid variations of the important functional regions of Nef gene were analyzed by Bio Edit and Mega6.0 software and the CTL epitopes shared by Nef gene sharing sequences in China and Nef shared sequences in international B subtypes were compared Happening. Results The amino acid sequences of N-terminal myristoylation signal region, protease processing region, acid region, Pak binding region, Pxx P region and other functional regions of HIV-1 B ’subtype strain were more conservative but there were 3 functional regions The mutation rate was 56.21% (R21E 24.09%, R21K 19.71%, R21Q 12.41%) with the mutation of E / K / Q on the codon 21 of variable length region with the mutation rate greater than 30% The mutation rate of E154 of COPI binding region EE154-155 by K was 32.85% and the S163 of double leucine motif Exxx LL160-165 was replaced by C by 30.66%. The CTL epitopes of the shared sequences of the 137 Nef proteins obtained in this study are consistent with the shared sequence CTL epitopes of HIV-1 B subtype in China, whereas those with two peptide epitopes compared with the international B subtype shared sequences Variation occurred. Conclusion The amino acid sequences of the most important functional regions and CTL epitopes of Nef protein of HIV-1 B ’subtype strains are conservative. However, there are 3 amino acid sites with mutation rate greater than 30% in the three functional regions, which may affect the virus induced Sickness.